/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.netbeans.modules.tasklist.trampoline;

import java.util.Iterator;
import java.util.NoSuchElementException;
import org.netbeans.spi.tasklist.TaskScanningScope;
import org.openide.filesystems.FileObject;
import org.openide.util.Lookup;

/**
 * Task scanning scope that has no files/folders.
 * 
 * @author S. Aubrecht
 */
class EmptyScanningScope extends TaskScanningScope {

    private final Iterator<FileObject> emptyIterator = new Iterator<FileObject>() {
        public boolean hasNext() {
            return false;
        }

        public FileObject next() {
            throw new NoSuchElementException();
        }

        public void remove() {
            throw new UnsupportedOperationException();
        }
    };
    
    /** Creates a new instance of EmptyScanningScope */
    public EmptyScanningScope() {
        super( null, null, null );
    }
    
    public boolean isInScope(FileObject resource) {
        return false;
    }

    public void attach(Callback callback) {
        //do nothing
    }

    public Lookup getLookup() {
        return Lookup.EMPTY;
    }

    public Iterator<FileObject> iterator() {
        return emptyIterator;
    }
}
